In this paper we describe four Indian in-service middle school mathematics teachers' shifts in their roles with respect to the textbook. The shifts occurred through participation in collaborative investigation on the topic of integers in professional development meetings. Analysis of teachers' talk in these meetings indicated a shift in teachers' role from reliance on textbook to using the knowledge of integer meanings to establish the connections between contexts and representations. We claim that this change in role occurred as a result of teachers developing knowledge of important ideas and representations in the professional development setting and identifying themselves as a member of a professional learning community which values students' understanding. We argue that since roles are constitutive of teachers' professional identity, the shifts in roles indicates how teachers' identity evolved towards being an empowered mathematics teacher who design tasks and responds to students to support articulation of ideas and developing reasoning in mathematics.